The present invention relates generally to an ophthalmologic apparatus, and more particularly to an ophthalmologic apparatus such as a retinal camera having an in-focus detecting optical system and a positioning detecting optical system.
In a prior art in which a conventional ophthalmologic apparatus such as a retinal camera is utilized, a fundus oculi of an inspected eye is illuminated with a beam of inspection light, a beam of light reflected by the fundus oculi is detected, and the fundus oculi of the inspected eye is observed or photographed.
However, in case of the conventional ophthalmologic apparatus, a reflection coefficient of the fundus oculi for the inspection light is low. Therefore, a quantity of the light reflected by the fundus oculi is not sufficient to observe the fundus oculi. Also, a contrast of the taken image of the fundus oculi on the inspected eye deteriorates. As a result, there is a problem that it is difficult to focus the fundus oculi of the inspected eye with an observation optical system or a photography optical system of the ophthalmologic apparatus.
Also, when a positional relationship between the inspected eye and the ophthalmologic apparatus undesirably changes, a flare caused by reflection of the inspected light on a cornea or a crystalline lens of the inspected eye is apt to enter the ophthalmologic apparatus. Therefore, the visibility of the image of the fundus oculi observed or photographed considerably deteriorates. As a result, there is another problem that a skilled operator is necessarily required to adjust the positional relationship between the inspected eye and the ophthalmologic apparatus on condition that any flare is not incident on the ophthalmologic apparatus.